Sudoku (数独 sūdoku) (sometimes spelled as Su Doku, but also called Number Place or Nanpure) is a puzzle that is very popular in Japan.
Sudoku puzzles are solved by logic and no math is required. It consists of a grid which is usually made up of nine rows, nine columns, and nine boxes that are separated by thicker, darker lines. To solve the puzzle, a person must fill in all the empty squares without using the same numeral twice in each column, row, or box, and without changing the numerals that are already in the grid.
We have prepared a Sudoku for National Numeracy Day for you to download and print for free. The download has both an easier and a more trickier version for those who like a challenge!